First off, there is silicon and then there is silicone with an 'e'.
Silicon is the element (on the periodic chart). It is a hard grayish crystalline material.
Silicone is an intentional misspelling that signifies a manufacturers formula for the silicone rubber. When a manufacturer says 100% silicone, it is not 100% silicon. For instance, the formulas that have funguscide are still labeled as 100% silicone. The funguscide is in the formula so it is still 100% silicone.
Silicone Rubber, 100% Silicone, or Silicone Caulk are all different formulas of effectively the same thing. They have their own unique properties. The same product across several different manufacturers will also have different properties because they all have their own unique formula.